Paragon’s square CS-19S digital glass clamshell kiln is easy to load, because the top lifts out of the way. Load the shelf first and then the glass onto the shelf. The CS-19S clamshell heats from the top for even heat distribution across the glass surface. The elements are completely embedded in a lightweight ceramic fiber top. The top has no element grooves or pins; this streamlined design helps eliminate dust in the firing chamber. The top of the lid is protected with a painted sheetmetal cover. The sheetmetal is bent to cover the sides of the lid and then welded at the corners. You will be amazed at the sturdy construction that has made Paragon kilns renowned among glass fusers. The self-adjusting lid floats at fusing temperatures.